1. Field of the Invention
The present invention generally relates to communication systems, and more particularly to a system and method for managing traffic in a mobile communication system.
2. Description of the Prior Art
In a multiplex sub-layer of a CDMA (Code Division Multiple Access) system, various kinds of traffic are converted into and transmitted as information having a physical layer SDU (Service Data Unit). When received, this information is separated and processed based on the kind of traffic. In the multiplex sub-layer, the type of multiplexing performed is based on a multiplex option determined in the course of contracting services between an MS (Mobile Station) provided with a mobile communication service and a BS (Base Station). Different kinds of traffic are combined in a predetermined way according to each of the multiplexing types.
FIG. 1 is a schematic block diagram showing a construction of a related-art mobile communication system. This system includes an MS 10 which transmits or receives various kinds of traffic such as a signaling traffic, a voice traffic, a data traffic to or from a BS 20 through an allocated traffic path.
The BS provides the MS not only with a voice service through an MSC (Mobile Switching Center) 30 and a PSTN (public Switched Telephone Network) 40, but also with a data service through a PDSN (Packet Data Service Node) 50 and an Ethernet. Here, the BS functions to multiplex the voice and data traffic transceived through the multiplex sub-layer (not shown) according to the corresponding multiplexing type.
FIGS. 2A to 2C show types of multiplexing, and FIG. 3 show a structure of transmission traffic multiplexed and transmitted in a multiplex sub-layer. Referring to FIGS. 2A to 3, the multiplex sub-layer converts and transmits received traffic into transmission traffic 300 according to a multiplex type predetermined by a previous contract. The transmission traffic includes a combination of a header 302, signaling traffic 304, primary traffic 306, and secondary traffic 308.
A block for the signaling traffic 304 (hereinafter, referred to as a “signaling block”) is stored with the signaling traffic. A block for the primary traffic 306 (hereinafter, referred to as a “primary block”) is stored with the voice traffic. And, a block for the secondary traffic 308 (hereinafter, referred to as a “secondary block”) is stored with the data traffic. For instance, in the case where the received traffic is the data traffic having a transmit rate of 4800 bit/sec, which is classified into multiplex type 1, the corresponding data traffic is transmitted over the primary block 306 having a size of 80 bits without the header 302 set by any value.
There is no conventional service capable of combining the voice traffic and data traffic. Thus, voice service is provided by transmitting the signaling traffic and the voice traffic in that order, while data service is provided by transmitting the signaling traffic and data traffic in that order.
As mobile communications technology continues to develop, it is anticipated that a technique for simultaneously providing voice and data services, i.e., an SVD (Simultaneous Voice and Data) service, will be needed so that signal processing procedures such as a scheme of exchanging signaling messages between the MS and BS for a corresponding SVD service can be standardized. Present standards do not provide details or any other information about combining voice traffic and data traffic or of allocating priority to data transmissions based on the type of traffic included in the transmissions.